Fuel-oil preheating device



June 5, 1928.

J. T. MOTARNAHAN FUEL OIL PREHEATING DEVICE 5 Sheets-Skeet 1 Filed Aug. 21. 1922 ATT FPNEY June 5, 1928.

J. T. McTARNAHAN FUEL OIL PEEK-{EATING DEVICE 5 Sheets-Sheet Filed Aug. 21, 1922 QR hm W ATTORNEY June 5, 1928.

J. T. M TARNAHAN FUEL OILPREHEATING DEVICE Filed Aug. 21, 1922 5 Sheets-Sheet 3 VE/VTOR- ATTORNEY break Patented June 1928.

UNITED STATES JOHN T. MCTARNAHAN, OF BOSTON, MASSACHUSETTS.

FUEL-OIL PREHEATING DEVICE.

Application filed August 21, 1922. Serial No. 588,072.

The invention to be hereinafter described relates to a fuel oil preheating device for introduction into a fuel oil pipe line leading to a burner or burners.

One type of burner or gun for fuel oil has passages leading to the nozzle of the burner, one for conducting the fuel oil, and the other for conducting air or other atomizing fluid which unites with the fuel oil and s up or atomizes the same for eflicient combustion.

Heretofore, considerable difliculty has been experienced in starting up or firing, owing to the heavy, sluggish character of the fuel oil. Blow torches and gas heaters have been applied to the pipe line leading to the burner for the purposeof raising the tem'-\ perature of the heavy fuel oil and changing the same to lighter liquid form formore ready atomization by the atomizing fluid, but these blow torches and gas heaters have been applied to the pipe line externally thereof. and the exposed flame from the heater has created such a fire risk that insurance authorities have seriously objected to' the use of such heaters, and in some states the insurance regulations in this respect are so strict as to prohibit the use of open flame heaters on the fuel oil pipe line.

One of the purposes of the present invention, therefore, is to provide fuel oil burning apparatus with a heater which will overcome the objections referred to. In carrying the invention into practical effect, in the present instance, an electric heater is provided which is located within the pipe line for conducting the fuel oil to the burner, and at a point adjacent to the burner, or sufficiently close to the point of combustion of the fuel to raise the temperature of the fuel I oil and change the same to a liquid form of suflicient lightness for ready atomization by the atomizing fluid. The construction is such that the heater is enclosed. does not produce a flame, and there is no danger of fire.

Another purpose of the invention is to provide a heater which may be readily introduced into the fuel oil pipe leading to the burner, and without alteration in the construction of the burner. -Thus, the heater is desirably suited for application to oil burning equipment which has already been installed. and without substantial alteration thereof.

In some installations a plurality of burners are employed for one boiler. The heater is desirably adapted for such installations,

since it may be readily introduced into the main fuel oil pipe leading to short branch pipes which deliver oil to the burners, but the heater will be suificiently close to the burners to effectively heat the oil delivered thereto. Thus, a single heater may serve to heat the fuel oil for the plurality of burners with desirable economy in' consumption of electric current.

With-theaforesaid and other .purposes in view, the character of the invention may be best understood by reference to the followmg description of one good form of apparatus embodying the invention shown in the acioinpanying drawings, wherein:

vided with a pair of burners and a heater in the fuel oil pipe line leading to said burners;

F ig. 2 on an enlarged scale is a. rear elevation of the burners, a portion of the atomizing fluid pipe leading thereto, aportion of the fuel oil pipe leading thereto, and a T-union interposed in the latter pipe pro.- vided with the heater;

Fig. 3 on an enlarged scale is a vertical longitudinal section through a portion of the fuel oil pipe and the heater carrying T-union and disclosing the heater mounted in the union with parts shown in section;

Fig. 4 is a horizontal section taken on line 4-4 of Fig. 3;

Fig. 5 on an enlarged transverse section taken Fig. 4; v I

Fig. 6 on an enlarged scale is a sectional detail to be referred to; and v Fig. 7 is a vertical longitudinalsection through one of the burners.

Referring to the drawings, 1 (Fig. 1) designates a boiler of the water tube type used for heating buildings, but obviously the invention may be applied to burners for any other type furnace.

I The boiler shown is provided with a pair.

scale is a vertical on.line 5 5 of of boiler or is a front elevation of a boiler proa burner or of burners 3 which pro ect through the front end of the boiler into the furnace thereof. The oil is conducted from a suitable source pf supply to the burners through piping The burners may be of any suitable construction, and in the'present instance each burner comprises an outer casing 15 (Fig. 7) conveniently of barrel form and having a breech or head '17 at one end thereof, and a nozzle 19 at the opposite end thereof.

An oil conducting member conveniently in the form of a tube 21, has one end connected to the head, and projects through the barrel 15 into the nozzle 19 where it is provided with a cap 23 having a delivery port 25 extending transversely to the length of the tube 21. The oil conductingtube 21 receives oil fromone of the branch pipes 11 through a transverse port 21 formed in the rear end of the breech. 4

Mounted within the casing nozzle 19 is an outwardly flaring nozzle 27 journalled on ball bearings 29 mounted on the outer end portion of the fuel oil tube 21. Attached to the flaring nozzle 27 is a turbine 31 adapted to be driven. by the atomizing fluid.

To contribute to the support ofthe oil conducting tube, a spider 33 may be mount-' ed on said tube-and have engagement with the inner surface of the outer nozzle 19. To lubricate the ball bearings 29, the spider 33 may be provided with a port- 35 communicatin with the chamber in the nozzle 27 containing the ball bearings, said portbein adapted to. receive lubricant through a tu e 37 extending parallel to the fuel oil tube 21 and having its rear end connected to a collar 39 mounted on the fuel oil tube 21. A tube 41 is connected to the collar 39, projects outward through the breech, and carries a cup 43 to receive a supply of lubricant. The construction is such that the lubricant may be fedfrom the cup 43 through the tubes 41 and 37 to the ball bearings.

The fuel oil tube21 has a diameter substantially less than that of the barrel 15,

thereby providing a passage 45 through which the compressed air or other atomizing fluid may be fed toward the delivery end of the burner. The compressed air will pass through the spider 33, strike the'vanes of the turbine 31, and thereby rotate the flaring nozzle 27. The compressed air will pass thence outward in an annular stream through the mouth between the nozzles 19 and 27, and there will meet the fuel oil delivered by the tube 21 and cap 23 to the inner nozzle. The compressed air will thoroughly break up or atomize the fuel oil and render the same in condition for efficient combustion.

The breech of the burner may be provided with a handle 47 adapted to be grasped in moving the burner to and from firing position. The breech of the burner may be mounted in a sleeve 49 carried by a neck 51 rising from the pipe 13,, referred to, for conducting the atomizing fluid to the burner.

73 mounted memes The burner may be locked. in active firing position by a yoke 53 pivotally mounted on the sleeve 49 and provided with a hand screw 55 which may be adjusted to engage the rear end of the breech and thereby securely hold the gun in the sleeve 49. When it is desired to withdraw the burner from the furnace, the hand screw 55 is released, and the yoke 53 is swung out of the path of the burner. Thereupon, the handle 47 may be grasped, and the burner may be withdrawn from its supporting sleeve 49.

To control the supply of atomizing fluid delivered to the burner, the disk valve 57 may be mounted in the neck 51 on a shaft 59 having one end projecting beyond the neck and bent to present a handle 61. 1 coil spring 63 encircles the shaft 59 and is confined between the neck and a pin in the shaft, frictionally to hold the shaft and disk valve in different positions of adjustment.

To heat the heavy fuel oil delivered by the vertical pipe 5, horizontal pipe 9 and branch pipes 11 to the burners so as to change the fuel oil to lighter form for ready atom1za-.

tion on meeting the atomizing fluid at the This heater, in the present instance, comprises a tube 65 (Figs. 3 and 4) of copper or other suitable material which may be bent into U-shape or other suitable form, and in the present instance, the U-shaped tube has a reverse bend, thereby enabling a tube of substantial length to be employed in compact space, and furnish the area of heating surface required. The legs 67 of the U- shaped tube may be suitably secured in a plug 69 which may be threaded into one end of the union 7.

Mounted within the tube 65 and spaced therefrom is a resistance member desirably in the form of a coil 7 0 of nickel chromium allo or other suitable material, said coil having close convolutions about an axis extending longitudinally of the tube. The ends of this coil may be wrapped about and pressed into circumferential grooves in wires 71 (Fig. 6) fitted tightly into sleeves in the ends of the legs 67 of the heater tube, and separated therefrom by short lengths of tubes 75 of mica or other suitable insulation. The wires 71 may extend through a block 77 and a base 79 secured by screws 81 to the plug 69. The ends of the wires 71 may be connected by binding screws 83 to terminals 85 rising from the block 77 and protected by a socket 87 which may be formed integral with the plug 69.

'A plug 89 of usual construction may fit and adapted to receive electric current from any suitable source.

The resistance coil tube and is embedded tion material 95, such, nesia, which is of heat 70 is spaced from the in pulverulent insulafor example, as magrefractory character. 15 pulverulent material may be tamped or pressed into a dense mass in the space in the tube unoccu ied by the resistance coil, and thereby e ectively insulate the latter from the tube.

The construction is such that the heavy fuel oil fed from the vertical pipe 5 to the horizontal pipe 9, will flow through the union 7 and over the copper tube 65 which extends through the union and a substantial distance into the pipe 9. Thus, the temperature of the fuel oil will be raised, and cause the latter to be changed from heavy to lighter liquid form as it approaches the burners. This lighter fuel oil will pass through the pi e 9 to the branch pipes 11 leading to the burners. The oil will enter the burners through the ports 21", and pass through the tubes 21 to the nozzles 27, where it will meet theatomizing fluid, and the condition of the oil will be such that it may be readily atomized by the compressed air or other atomizing fluid. I

When it is desired to fire the burners, it is merely necessary to turn on the electric current to the heater.. Then when the fuel oil is turned on and admitted to the burners, its temperatur will be quickly raised so that the fuel oi may be readily ignited at the delivery ends of the burners, and this is accomplished without the use of a blow torch, gas heater, or other heating device having an exposed flame. As a result, the burners may be quickly and easily fired, and without any fire risk. Since the heater is incased, and in the present instance, is located within the fuel oil pipe adjacent to the burner, it is inconspicuous, out of the wa and does not materially add to the bulk of the apparatus. The heater may be readily a plied not only to new installations, but al so to old installations, it being merely necessary to introduce the T-union into the fuel oil pipe line and insert the heater in the union, so that it projects into the pipe line in the path of the fuel oil flowing therethrough.

The heater is simple and cheapin construction. durable and reliable in operation, and requires but a small amount of electric current, with resultant economy.

The heater mounted in the apparatus as described, is, as stated, highly desirable in firing or starting the burners, but if desired,

.on the fuel oil pipe line the current to the heater may be sup lied continuously during the operation. of the burner, in order torender the fuel in lighter or more volatile condition.

i fter the electric heater has raised the temperature of the fuel oil sufficiently hi h to enable ready firing of the burner, t e heater may be employed to continue the heating of the fuel oil until the burner has developed suflicient heat to generate steam in the boiler. Then the electric current to the heater may be shut off, and the steam generated by the boiler may be utilized to heat a heater device which may be desirably in the form of a steam jacket located at a point back of the electric heater. serve to change the the union cont-ainin This steam jacket wil fuel oil from heavyto lighter liquid form, so as to enable ready atomization of the fuel oil, and without the expense of electric current during the continued operation of the burner or burners.

While the invention has been described more particularly with reference to its application to a burner employing fluid for atomizing the fuel oil, yet it is not limited thereto, since it also may be ap lied desirably to fuel oil burners in whic 1 the oil is broken up into the form of spray mechanically and without the use of atomizing fluid.

It will be understood that the invention is not limited to the specific embodiment shown, and that various deviations may be made therefrom without departing from the spirit and scope of the appended claim.

What is claimed is The combination of a burner, a continuous pipe for conducting heavy fuel oil to the burner, a union connected to the pipe at a point adjacent to the burner, a plug connected to the union, a tube secured to the plug, of substantial length, extending longitudinally of the pipe and adapted for contact with the fuel oil flowing through the space between the tube and the inner surface of the pipe, an electric resistance member extending through and spaced from the inner surface of the tube and adapted for connection with a source of electricity there by to heat the resistance member, and pulverulent insulation material packed in the tube between the resistance member and the inner surface of the tube and preventing the member from contact with the tube, said pipe and tube being relatively proportioned so that the heat from the resistance member will be effective to give the fuel oil passing through the space bet-ween the tube and pipe :1 free flowing character suitable for ready atomization and combustion at the burner.

JOHN T. MoTARNAHAN. 

